Sealing Foam Panels with a Compression-Generating Joint

ABSTRACT

A method of joining panels of foam material such that edges are compressed into panel surfaces to provide a secured and effectively sealed structure is disclosed. Panels in an orthogonal relationship to each other, which are made of foam (or other materials not intended to be load bearing) can be joined by compressing the outer side of one of the panels into the edge surface of an adjoining panel. This is done using two plates, one resting on the outer side of the first panel, and one inserted into the side of the second panel, where the plates are connected by a bolt, screw or wire under tension.

FIELD OF THE INVENTION

The invention relates to a method of sealing foam panels, usingcompression-generating joint, rather than adhesion.

BACKGROUND

Containers made of foam insulating materials, including insulatedshipping containers, provide excellent insulation for their contents.Such insulated shipping containers are widely used to maintain thetemperature of shipped materials near refrigeration levels, therebypromoting preservation of the material. Such containers can be made froma number of foam materials including expanded polystyrene (EPS),extruded polystyrene (XPS) and Urethane. Such containers are generallymade by molding, or they can be formed from bonded panels. Bonding worksnearly as well as molding to provide hermetic sealing at the edges, andmaintain comparable insulating properties.

The disadvantages of bonding or molding is the cost and time involved.Molding can generally only be done by the container manufacturer, andthus there is a limit on the size and shapes of containers available.Smaller or larger containers are desirable for shipping materials ofdifferent dimensions. Bonding can be done on-site, but it time-consumingand labor-intensive to accomplish. Also, unless done in accordance withspecifications, it may result in a container which is considerablyweaker than a molded container. Thus, a simple, fast, inexpensive methodof joining insulating panels, which achieves a strong container, isdesirable.

SUMMARY

The joining panels of foam materials such that edges are compressed intopanel surfaces to provide a strong effectively sealed structure, isdisclosed. Panels in an orthogonal relationship to each other, which aremade of foam (or other materials not intended to be load bearing) canjoined by compressing the outer side of one of the panels into the edgesurface of an adjoining panel. This is done using two plates, oneresting on the outer side of the first panel, and one inserted into theside of the second panel, where the plates are connected by a bolt,screw or wire under tension.

The panels can be any foam material, including expanded polystyrene(EPS), which has sufficient structural rigidity and can hold the secondplate when it is inserted in place. This can be accomplished quickly bysimply heating the second plate to melt a slot to accommodate it in theside of the second panel, which is then connected with a threaded boltto a first plate positioned on the outer side of the first panel. Othermeans of connecting the plates are also possible, such as connectionwith a wire under tension, passing through and joining the plates. Othermeans of making a slot in the second panel are also possible, such ascutting, or simply pushing the second plate into place unheated.

The plates can be placed in position using a template, which has atleast two substantially planar, orthogonal sides. The template has aslot to accommodate the second plate in proper position for insertioninto the second panel. Where the plates are joined with a treaded boltor screw, the second plate has a hole positioned to align with a hole inthe first plate, and the template has a hole in the appropriate sidewhich aligns with the holes in the first and second plates.

A hole in the foam panels to accommodate the bolt can be made bydrilling, or simply by heating the bolt or screw and pushing it intoplace through the foam, then removing it (or even inserting itunheated). After the template is removed, tightening the bolt (ortensioning a wire or another joining mechanism) pulls the panels againsteach other, compresses the foam at the region where the panels arejoined, and creates a secure, hermetically sealed joint. The bolt shouldbe tightened until both foam panels mate with no gaps, and the plate onthe end compresses the foam by approximately the thickness of the plate.

An advantage of the joining mechanism described here is that appliancescan be readily added to the plates, and can be readily secured to thefinal product, by securing an appliance to the second plate by passingthe bolt through a hole in such an appliance. Such appliances couldinclude hinges, straps or brackets.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plan view from one side of two panels joined by a boltthrough two plates.

FIG. 2 depicts a side view of an alignment bracket for the plates ofFIG. 1 in position on two panels.

FIG. 2A is a plan view of the alignment bracket.

FIG. 3 is a side view the alignment bracket of FIG. 2, with one of theplates in position.

FIG. 4 is a plan view of the alignment bracket and the one platepositioned as in FIG. 3.

DETAILED DESCRIPTION

In FIG. 1, an upper foam panel 10 is joined to a the edge surface of afoam panel 20, using a plate 12 resting on the outer surface of panel10, which is drawn towards plate 14 (inserted into the panel 20), usinga threaded screw or bolt 16. Bolt 16 threads into mating threads inplate 14 and passes through aligned holes in panels 10 and 20. Asdescribed above, the holes in the panels 10 and 20, and a slot in panel20 for inserting plate 14, can be made by drilling/cutting; melting orsimply pushing through the foam material of the panels. Tightening bolt16 mates the adjoining surfaces of panels 10 and 20 and creates anairtight seal.

FIGS. 2 and 2A depicts the alignment template 22 used for aligning theplates 12 and 14. Template 22 includes a slot 24 through which plate 14is inserted, so as to position it correctly so that the treaded hole inplate 14 aligns with a corresponding hole in plate 12 and hole 25 thetemplate 22.

FIG. 3 and FIG. 4 depict the template 22 and the bolt 16 in place in thepanels 10 and 20. Template 22 would be removed once plate 14 is in placeand aligned with hole 25, plate 12 would be placed in position on theupper surface of panel 10, bolt 16 would be tightened to bond and sealpanels 10 and 12.

Hinges, straps or brackets or other appliances can be attached to thejoined panels 10 and 20 (and the resulting box) by, for example,securing them using the bolt 16. Where several such joints are made in abox, more bolts are available for securing such appliances.

The terms, expressions and examples herein are exemplary only, and notlimiting, and the scope of the invention is defined only in the claimswhich follow and includes all equivalents of the claimed subject matter.

1. A method of joining panels of foam materials by compression,comprising: placing the panels to be joined in an orthogonalrelationship to each other, such that an edge surface of a first panelrests on a first planar surface of a second panel; inserting a firstplate, having a first hole through it, into the first panel such thatthe first plate's planar surface lies parallel to the planar surface ofthe second panel; placing a second plate having a second hole through iton the planar surface of the second panel which opposes the first planarsurface, such that the first and second holes are aligned; joining thefirst and second plates with a bolt, screw or wire passing through thefirst and second holes; and tensioning the bolt or wire such that thefirst and second plates are pulled towards each other and the edgesurface of the first panel is pressed into the first planar surface ofthe second panel.
 2. The method of claim 1 wherein the first hole isthreaded and the bolt threads into the threaded first hole to providetension.
 3. The method of claim 1 wherein the first and second platesare sheet metal.
 4. The method of claim 1 wherein the panels are made ofexpanded polystyrene.
 5. The method of claim 1 further including thestep of heating the first plate or the area of the first panel whichaccommodates the first plate.
 6. The method of claim 2 wherein the boltis tensioned such that the edge surface of the first panel mates withthe first planar surface of the second panel.
 7. The method of claim 2further including providing a template having two orthogonal sides, andhaving a slot in one side to accommodate the first plate and a templatehole in the other side, the slot and the template hole designed suchthat when the first plate is inserted into the slot, the first hole isaligned with the template hole, and when the second plate is in place,the second hole is also aligned with the template hole.
 8. The method ofclaim 7 wherein the template hole is larger than the diameter of theshaft of the bolt.
 9. The method of claim 2 wherein the bolt passesthrough a hole in an appliance, such that the appliance is held securelyin place when the bolt is tensioned.
 10. The method of claim 9 whereinthe appliance is a hinge, a strap or a bracket.
 11. A method of formingan insulated container comprising: placing four panels in an orthogonalrelationship to a fifth panel, such that an edge surface of each of thefour panels rests on a first planar surface of the fifth panel;inserting an insertion plate, having a plate hole through it, into eachof the four panels such that the each insertion plate's planar surfacelies parallel to the planar surface of the fifth panel; placing one ormore plates on the planar surface of the fifth panel which opposes thefirst planar surface, such that plate holes are aligned with holes in asecond plate; joining the insertion plates with the second plates with abolt, screw or wire passing through an aligned plate hole and a hole inthe second plate; and tensioning the bolts or wires such that theinsertion plates are pulled towards second plate and the edge surfacesof the four panel are pressed into the first planar surface of thesecond panel.
 12. The method of claim 11 wherein the plate holes arethreaded and the bolts or screws thread into the threaded plate holes toprovide tension.
 13. The method of claim 11 wherein the insertion platesand the second plates are sheet metal.
 14. The method of claim 11wherein the panels are made of expanded polystyrene.
 15. The method ofclaim 11 further including the step of heating the insertion plates orthe area of the four panels which accommodates the insertion plate. 16.The method of claim 14 wherein the bolts or screws are tensioned untilthe edge surfaces of the four panels mate the first planar surface ofthe second panel with no gaps, and the second plate compresses theexpanded polystyrene by approximately the thickness of the second plate.17. The method of claim 11 further including providing a template havingan upper side and one or more orthogonal sides, and having a slot ineach orthogonal side to accommodate an insertion plate and one or moretemplate holes in the upper side, the slots and the template holesdesigned such that for each insertion plate inserted into a slot, theplate holes are each aligned with a template hole.
 18. The method ofclaim 17 wherein the template holes are larger than the diameter of theshaft of the bolt.
 19. The method of claim 12 wherein the bolt passesthrough a hole in an appliance, such that the appliance is held securelyin place when the bolt is tensioned.
 20. The method of claim 19 whereinthe appliance is a hinge, a straps or a bracket.